Description of problem:
Glusterfsd appears overcommited memory

Version-Release number of selected component (if applicable):
v3.7.6 / RHEL v6.6

How reproducible:
Glusterfsd ran for ~10 days and then seeing memory overcommitted

Steps to Reproduce:
Nothing special, just run glusterfsd for ~10 days. The cluster node has 24G RAM with 20 glusterfsd processes

Actual results:
/proc/meminfo:
 MemTotal:       24414040 kB
 MemFree:         1158296 kB
 Buffers:          405876 kB 
 Cached:         18039396 kB 
 ..
 CommitLimit:    20497320 kB
 Committed_AS:   44178840 kB
 VmallocTotal:   34359738367 kB 
 VmallocUsed:      630888 kB 
 VmallocChunk:   34344910868 kB 

Expected results:


Additional info:
Ran 'echo 2 > /proc/sys/vm/drop_caches' to drop the cache, MemFree increased:
 MemTotal:       24414040 kB
 MemFree:        18648448 kB
 Buffers:          436724 kB
 Cached:           673008 kB
But Committed_AS remain high:
 CommitLimit:    20497320 kB
 Committed_AS:   44178840 kB
 VmallocTotal:   34359738367 kB
 VmallocUsed:      630900 kB
 VmallocChunk:   34344910868 kB